Engineering Commons^™

The Failure Of A Cut Slope On The Tuen Mun Road In Hong Kong, S. R. Hencher, R. P. Martin

International Conference on Case Histories in Geotechnical Engineering

The investigation and analysis of two landslides in a recently-constructed cut slope in weathered granite are described in detail. The failures are attributed partly to complex geological conditions which caused a perched water table to develop in the major scar. Adverse jointing contributed to the minor failure. The original site investigation was not sufficiently detailed to identify the important geological and hydrogeological aspects of the site. Conclusions are drawn with respect to the usefulness of back analysis for identifying failure mechanisms.

The Foundation Of The Right Bank In Wadi-Zarat Dam, M. A. Benltayf, M. Atalla, K. Rabah

International Conference on Case Histories in Geotechnical Engineering

The geotechnical engineering characteristics of a calcareous crust formation are evaluated in order to determine the feasibility of its stability under the right bank of Wadi Zarat Dam. The crust is a rock similar, extremely heterogeneous, material with location of collapsing susceptibility when saturated. The formation is caverned and locally very permeable and can present a risk of losing the reservoir water, dissolution, settlement, and piping. In this case study, several alternatives to treat the crust formation are presented, discussed, and compared. Rational justifications for the adopted solution are given and the predicted performance during operation of the dam is …

Assessment Of Seismic Stability Of Earth Dams By Comparative Methods, Rodney J. Huang, Marshall L. Silver

International Conference on Case Histories in Geotechnical Engineering

Seismic stability of embankment dams and their foundations has been a major concern in recent years because of notable incidents such as the behavior of the Lower San Fernando dam in the San Fernando Earthquake. Sophisticated and involved analytical methods have been developed to study the behavior of dams in earthquakes. Predicted seismic behavior agrees well with measured seismic behavior in the few case histories that exist of seismically induced distress in dams. However, for many dams, the level of information or effort required for a complete sophisticated seismic analysis is not warranted. For such cases it is possible to …

Earthquake Damages To Earth Dams And Levees In Relation To Soil Liquefaction And Weakness In Soft Clays, W. S. Wang

International Conference on Case Histories in Geotechnical Engineering

In this paper, a number of case histories of typical earthquakes dams and levees which have been damaged by earthquakes occurred in past two decades in China are reported in some details along with data obtained from field and laboratory investigations as well as some analytical results. These damages are mainly due to liquefaction of saturated cohesionless or less cohesive soils and slippage in weak soft clays. It is concluded that, in order to avoid severe earthquake damages, earth dams and levees should be compacted to dense state and any liquefiable soils and weak soft clays in foundations should be …

General Report For Theme Five Case Histories In Geotechnical Earthquake Engineering, Gonzalo Castro

International Conference on Case Histories in Geotechnical Engineering

No abstract provided.

Liquefaction Of A Soil Deposit During An Earthquake, Shamsher Prakash, M. K. Gupta

International Conference on Case Histories in Geotechnical Engineering

Large number of cases have been rep or ted where liquefaction has occurred during the earthquake, but only in a few cases, soil report in the zones of liquefaction are available. A wide spread damage because of liquefaction of soil deposit was observed during tile Niigata Earthquake of 1964 in Japan. A very systematic study on soil exploration in the zone of liquefaction was carried out and is well reported. Two sites were selected for the analysis from Niigata in the same area (i) where heavy damage occurred (ii) where no damage occurred. A case study was made using two …

Liquefaction Potential Evaluation For Arcadia Dam, J. R. Wagner

International Conference on Case Histories in Geotechnical Engineering

The paper presents the studies performed as part of the liquefaction potential evaluation for Arcadia Dam. The evaluation was performed by the Tulsa District, Corps of Engineers, using a modification of the "Simplified Procedure" developed by H. B. Seed. A discussion of the various decisions, judgements and procedures used to adapt the required studies to the site specific conditions is presented along with a description of drilling, sampling, sample handling, and laboratory testing. The most significant finding from the evaluation is that a useful relationship exists between standard penetration test (SPT) blow count values, laboratory cyclic shear strength and soil …

Liquefaction Potential Of Silty Sand Site, H. Dezfulian, N. D. Marachi

International Conference on Case Histories in Geotechnical Engineering

Dynamic properties of subsurface soils at the site of a proposed nuclear power plant were determined through extensive field and laboratory tests. The liquefaction potential of the granular soils underlying the site were obtained by using field data obtained from both standard penetration resistance and cone penetration tests as well as from laboratory data obtained from cyclic triaxial compression tests. The analyses showed that comparable factors of safety may be obtained from both field and laboratory test data.

Liquefaction Risk Evaluation During Earthquakes, Qiao Taiping, Wang Chenchun, Weng Lunian, Liu Huishan

International Conference on Case Histories in Geotechnical Engineering

A simplified method is herein presented to evaluate liquefaction risk, where we modified the form of liquefaction potential index suggested by Iwasaki, Tokida and others (1980, 1982). Based upon the investigations of structure damage induced by soil liquefaction during Tangshan earthquake, four categories for evaluating liquefaction risk and the principles of engineering treatment are proposed. Several typical liquefaction sites are analyzed by this method.

Research On The Permeability And Earthquake Damage Of An Earth Dam Foundation, Zhi-Jie Zhu, Wen-Kai Liu

International Conference on Case Histories in Geotechnical Engineering

The experiences on geological investigation, permeability test, prediction of seepage failure patterns and the earthquake damage of an earth dam foundation are presented in this paper. Basing on the monitoring data and seismic records observed from the seismic station on the dam, the prediction of reservoir induced earthquake and possibility of liquefaction are analysed.

A Case Study On Decreasing Vibration Of Machine Foundations And Structures, Xikang Wang

International Conference on Case Histories in Geotechnical Engineering

Foundations under 3 compressors rested on a clay base. With the secondary exciting frequency falling into resonance region, the vibration velocity of foundations reached 8.96 mm/s exceeding the permissible limit. It was reduced to 4.0 mm/s through the use of combined foundation, thus ensuring normal production.

Behavior Of Compressor Foundation – Predictions And Observations, Shamsher Prakash, Vijay K. Puri

International Conference on Case Histories in Geotechnical Engineering

In a Compressor foundation undergoing excessive vibrations, its amplitudes at operating frequency and natural frequency in free vibrations were monitored. Also in-situ dynamic properties were determined to check design and predict its response. Since the soil constants are strain depondent, two sets of computations were done (1) from the known soil constants and permissible amplitudes and (2) from the known soil constants and the observed amplitudes. The soil constants were corrected for confining pressure and relative density of the non-cohesive soil also. Both weightless spring theory (Barkans’ Method) and elastic half space theory were used in predicting the response. A …

Geotechnical Problems In A Bridge Over Corinth Canal, S. G. Christoulas, N. A. Kalteziotis, G. K. Tsiambaos

International Conference on Case Histories in Geotechnical Engineering

The railroad bridge of Corinth Canal was founded in a stable tectonic block (horst) consisting of neogene marly limestones, marls and sands. After the last strong earthquake of 24th February 1981 an extension of existed subvertical joints, directed E-W, was observed close to the northern bridge abutment. A geotechnical study was carried out for the detection of the causes which created these phenomena and for the design of probable reinforcing measures. From the results of site investigations and laboratory tests and after considering the slope stability, it was concluded that the only risk for the abutment is the progressive change …

Pittsburgh's Mt. Lebanon Tunnels- Case History, G. L. Butler, B. P. Cavan, F. K. Mussger, G. W. Rhodes, H. T. Whitney

International Conference on Case Histories in Geotechnical Engineering

Discussions of basic design philosophy and comparison of alternative contract bid options are presented. Also discussed are descriptions of field monitoring activities with respect to the construction methods, ground response, installation of materials and their performance. Finally, conclusions are reached relative to the NATM philosophy as applied to this project and its place as a design process within the context of United States underground construction practice.

Shale Pit Slopes - A Case History, D. H. Shields

International Conference on Case Histories in Geotechnical Engineering

The preliminary design for 180 metre high open pit mine slopes in shale is described. Given the complex geology and material properties, the first choice would have been to use reliability theory. The state-of-the-art of probabilistic methods in geotechnical engineering precludes this, and a deterministic approach to design was resorted to instead.

Squeezing Problems In Indian Tunnels, J. L. Jethwa, A. K. Dube, B. Singh, Bhawani Singh

International Conference on Case Histories in Geotechnical Engineering

Case histories of three Indian tunnels indicate that squeezing conditions are created due to plastic flow of rock masses under the influence of high cover pressures. These examples emphasize that a tunnel experiencing squeezing conditions must be allowed to deform to optimize support costs and avoid delays. Allowance for desirable tunnel deformations must, therefore, be made while planning the size of excavation.

Field data has shown that a flexible support system of compressible backfill and steel ribs may be used as an alternative to shotcrete support which is unpractical in Indian tunnels excavated largely by conventional methods. Instrumentation indicates that …

Stillwater Tunnel, Central Utah Project, Utah - Case History, R. S. Sinha, K. D. Schoeman

International Conference on Case Histories in Geotechnical Engineering

Described is the case history of Stillwater Tunnel highlighting the aspects of design, construction, instrumentation, and contracting procedures, which on September 14, 1983, culminated in the successful holethrough for this 8.03-mile (12.92-km) long water conveyance tunnel. The case study demonstrates that for a successful project it is essential to carefully select a ·compatible excavation system and a contractor who has the incentive to complete the project within the resources of available time and budget. The study illustrates the weaknesses in the current state of the technology for design and construction of deep and long tunnels and urges an improvement of …

The Stability Of Underground Power Chambers In The Brittle Rock, Weishen Zhu, Kejun Wang, Guangzhong Peng

International Conference on Case Histories in Geotechnical Engineering

The statistical analysis has been executed for the phenomenon of disk cores in the dam site, which has been compared with the condition of high geostresses. The mechanism to form disk cores and the stress state and energy distribution around underground power houses have been analysed with FEM. In addition, the modelling test to investigate the stability of underground house with block material is introduced. Finally some practical conclusions are proposed.

A New Method Of Stabilization Of Soft Soils, M. A. Aziz

International Conference on Case Histories in Geotechnical Engineering

A new method of stabilization of soft soils using split-bamboo poles filled up with coconut coir wicks has been described. The results of the field tests of this new method on an actual construction site have been critically analysed and discussed.

Construction Of The Key Lake Tailings Facility, R. B. Knight, J. P. Haile

International Conference on Case Histories in Geotechnical Engineering

Construction of the Tailings Storage Facility for the Key Lake Project a major uranium mine in northern Saskatchewan, Canada, was completed in June, 1983. Principal design features of the tailings facility are an underseal and underdrainage system over the entire area, systematic deposition of the tailings in thin layers using the sub-aerial technique, and continuous removal and recycling of all surface water and underdrainage outflows to the mill for treatment. These features are designed to achieve a consolidated, drained tailings deposit suitable for immediate decommissioning QD completion of milling, and with a minimal potential of long term seepage. The design …

Dewatering, Hydraulic Failure And Subsequent Analysis Of A Sheeted Excavation, G. E. Bauer

International Conference on Case Histories in Geotechnical Engineering

A 16m deep sheeted excavation failed by piping of the base. The sequence of events leading to this failure is described and served as a field case to study the hydraulic nature of the project using flownet, electrical analogy and finite element methods.

Effectiveness Of A Slurry Cutoff Wall At Loeffel Site, G. W. Lee Jr., S. K. Bhatia, G. A. Swenson Iii, S. P. Clemence

International Conference on Case Histories in Geotechnical Engineering

In recent years slurry cutoff walls have been successfully employed to mitigate seepage and isolate liquid waste and leachate in the groundwater environment. However , a success of the slurry cutoff wall depends on the hydrological condition of the site. A post construction and pre-construction groundwater budget analysis can demonstrate the effectiveness of a slurry cutoff wall. In this paper, a detailed groundwater budget analysis of Loeffel site in the Southwestern Rensselaer County of New York is discussed. The analysis shows that the use of a slurry cutoff wall effectively mitigates the release of contaminated groundwater from the site.

Expansive Soil Pavement Design Using Case Studies, G. R. Mckeen, R. L. Lytton

International Conference on Case Histories in Geotechnical Engineering

A study of the field behavior of airport pavements on expansive soils was made for the purpose of developing design procedures for expansive soil areas. Through theoretical developments, computer simulation and empirical calibration a pavement thickness design procedure was developed. The selection of pavement thickness using the method insures a stiff enough pavement to reduce differential movements to acceptable levels based on calculated aircraft response. Differential movements are calculated using a soil model developed from recent concepts of expansive soil behavior. A soil pavement interaction model was derived for calculating the restraint provided by pavement stiffness.

Failure Of A Salt Aragonite Storage Pad, Yong S. Chae

International Conference on Case Histories in Geotechnical Engineering

A case study of the performance and failure of an aragonite and salt storage pad covering an area of approximately 250 ft. (76 m) square built on marginal subsurface conditions is reported. A detailed analysis of the failure illustrates the importance of thorough exploration of subsurface conditions and field instrumentation to monitor the performance of such storage pads during and after the loading period.

Foundation Movement Monitoring Of Heavy Structures – A Case History, M. R. Lewis, A. Sanver

International Conference on Case Histories in Geotechnical Engineering

Accurate monitoring of settlement beneath the main structures of a nuclear power plant not only demonstrates the stability of the structures, but also confirms predicted settlements, thereby verifying the geotechnical parameters used in the design. At the Grand Gulf Nuclear Station near Port Gibson, Mississippi, rebound and settlement monitoring has been continuous since the start of site excavation in 1974. As a result, actual settlements have been shown to be close to the predicted levels. This paper discusses the planning, installation and monitoring of the settlement instrumentation and reviews the factors that were important to the choice of instrumentation.

Foundations On Friction Creep Piles In Soft Clays, Sven Hansbo

International Conference on Case Histories in Geotechnical Engineering

In this lecture, a new principle for design of building foundations on friction piles in soft, cohesive soils is presented. Four case records on buildings designed according to the new principle are analysed in respect of total and differential settlement. In two cases, a comparison has been made with buildings on conventional friction piles. The savings in foundation cost of the buildings designed with creep piles is evaluated in relation to buildings designed with conventional friction piles. The lecture is a synthesis of research and development carried out together with Leif Jendeby, M.Sc., Chalmers University of Technology and Rolf Källström, …

Ground Response, Baltimore Lexington Market Tunnels, J. G. Engels, S. J. Calabrese

International Conference on Case Histories in Geotechnical Engineering

Soil response data and the results of soil deformation analyses are presented for twin tube rapid transit tunnels constructed in soil. The data collection and analyses were performed during the construction of the Lexington Market Line Tunnels in Baltimore, MD between 1977 and 1980. Sources and volumes of ground loss around the tunnels and the resulting ground surface settlement patterns are discussed. Analyses are presented indicating that substantial volume expansion of the soil over the tunnel occurred during construction. Comparisons are made to similar analyses of data reported in the literature for other tunnels driven in similar geologic conditions.

A New Version Of Rectification For The Leaning Structures And Foundations, Yi-Ji Wang, Jian-Xin Yuan

International Conference on Case Histories in Geotechnical Engineering

A new version of the rectification technique tor the leaning structure and foundation developed by Wuhan Foundation Engineering Center was used to restore the tilted columns to their original position. The main idea of this new method is to apply adjusting loads on the foundation through anchors or short piles. According to the tilting conditions the anchors or piles can be installed at one side or at both sides of the tilting foundations. The loads can be applied in successive increments until the final desired positions were reached. By using this technique a tilted warehouse was completely restored to its …

Behaviour Of Bridge Abutment On Fractured Chalk, A. Marsland, A. P. Butcher

International Conference on Case Histories in Geotechnical Engineering

Loading tests on 865 mm diameter plates showed that the fractured chalk was much more compressible than at other sites on the same deposit but it was still considered that slab foundations would be adequate for the bridges at most locations. Detailed measurements have been made on one of the bridge abutment foundations both during and following construction. Measurements were made of vertical pressures applied to the ground, lateral earth pressures acting on the abutment wall, settlements of the foundation slab, tilt of the wall, and vertical displacements in the ground below the foundations. These observations confirmed the adequacy of …

Caisson Design By Instrumented Load Test, D. J. Lane

International Conference on Case Histories in Geotechnical Engineering

Three instrumented axial load tests were performed on 42 inch diameter caissons (drilled piers). These caissons were installed in marine sediments of dense sand overlain by soft sand-clay mixtures. Correlations were made with the Standard Penetration Test to develop design relationships. Production caissons were then designed based on these relationships. Test caissons were approximately 54 feet long and installed by the slurry displacement method. Test loads were carried to 1,000 tons. Mustran cells were used to determine loads in the caissons at different depths. Resulting data is presented graphically as load versus settlement, load versus depth (load distribution), and side …